This invention generally relates to a method and device for receiving input signals with a receiver from multiple systems. More particularly, this invention relates to a method of operating a low noise amplifier for a receiver receiving input from multiple systems.
A receiver for automotive system applications typically receives signals for a remote keyless entry system. In many instances it is desirable for the receiver to recognize and receive signals from a remote transmitter at increased distances. An external low noise amplifier (LNA) installed with the receiver provides increased signal sensitivity that translates into the capability of receiving signals from increased distances. The LNA provides an increased gain to surrounding signals that increases the range and sensitivity of the receiver.
Disadvantageously, the increased gain provided by the external LNA reduces large signal capability and therefore increases the probability that the receiver is blocked by an interfering signal. Many receivers are utilized for multiple automotive systems such as both a remote keyless entry system and a tire pressure monitoring system. The signals from the tire pressure monitoring system do not require amplification, as they are located on the vehicle. However, external interference received by the receiver due to the increased sensitivity provided by the LNA system could cause undesirable interference with such signals.
Accordingly, it is desirable to develop a method of controlling an external low noise amplifier to provide the desired increase in receiver range and sensitivity while also providing reliable receipt of other signals.